Given numRows, generate the first numRows of Pascal's triangle.
For example, given numRows = 5, Return
[ [1], [1,1], [1,2,1], [1,3,3,1], [1,4,6,4,1] ]
C++
class Solution { public: vector<vector<int> > generate4(int numRows) { vector<vector<int>> dp(numRows); if (numRows < 1) return dp; dp[0].push_back(1); for (int i =1; i < numRows; i++){ dp[i].push_back(1); for(int j = 1; j < i; j++) dp[i].push_back(dp[i-1][j-1] + dp[i-1][j]); dp[i].push_back(1); } return dp; } vector<vector<int>> generate(int numRows){ vector<vector<int>> dp(numRows); for(int i = 0; i < numRows; ++i){ dp[i].push_back(1); for(int j = 1; j < i; ++j) dp[i].push_back(dp[i-1][j-1] + dp[i-1][j]); if (i>0) dp[i].push_back(1); } return dp; } };
转载于:https://www.cnblogs.com/vercont/p/10210264.html
